LeNRT1.1 Improves Nitrate Uptake in Grafted Tomato Plants under High Nitrogen Demand
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Departamento de Ciencias Vegetales, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, Santiago 7820436, Chile
2
Centro UC Desierto de Atacama, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, Santiago 7820436, Chile
3
Departamento de Producción Agrícola, Facultad de Ciencia Agrarias, Universidad de Talca, Avenida Lircay S/N, P.O. Box 747, Talca 3462227, Chile
*
Author to whom correspondence should be addressed.
Int. J. Mol. Sci. 2018, 19(12), 3921; https://doi.org/10.3390/ijms19123921
Received: 23 October 2018
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Revised: 3 December 2018
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Accepted: 3 December 2018
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Published: 7 December 2018
(This article belongs to the Special Issue Regulation of Mineral Nutrients Homeostasis and Their Crosstalk in Plants)
Grafting has become a common practice among tomato growers to obtain vigorous plants. These plants present a substantial increase in nitrogen (N) uptake from the root zone. However, the mechanisms involved in this higher uptake capacity have not been investigated. To elucidate whether the increase in N uptake in grafted tomato plants under high N demand conditions is related to the functioning of low- (high capacity) or high-affinity (low capacity) root plasma membrane transporters, a series of experiments were conducted. Plants grafted onto a vigorous rootstock, as well as ungrafted and homograft plants, were exposed to two radiation levels (400 and 800 µmol m−2 s−1). We assessed root plasma membrane nitrate transporters (LeNRT1.1, LeNRT1.2, LeNRT2.1, LeNRT2.2 and LeNRT2.3) expression, Michaelis‒Menten kinetics parameters (Vmax and Km), root and leaf nitrate reductase activity, and root respiration rates. The majority of nitrate uptake is mediated by LeNRT1.1 and LeNRT1.2 in grafted and ungrafted plants. Under high N demand conditions, vigorous rootstocks show similar levels of expression for LeNRT1.1 and LeNRT1.2, whereas ungrafted plants present a higher expression of LeNRT1.2. No differences in the uptake capacity (evaluated as Vmax), root respiration rates, or root nitrate assimilation capacity were found among treatments.
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Keywords:
nitrate transporters expression; growth rate; root membrane transporters; root respiration
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MDPI and ACS Style
Albornoz, F.; Gebauer, M.; Ponce, C.; Cabeza, R.A. LeNRT1.1 Improves Nitrate Uptake in Grafted Tomato Plants under High Nitrogen Demand. Int. J. Mol. Sci. 2018, 19, 3921. https://doi.org/10.3390/ijms19123921
AMA Style
Albornoz F, Gebauer M, Ponce C, Cabeza RA. LeNRT1.1 Improves Nitrate Uptake in Grafted Tomato Plants under High Nitrogen Demand. International Journal of Molecular Sciences. 2018; 19(12):3921. https://doi.org/10.3390/ijms19123921
Chicago/Turabian StyleAlbornoz, Francisco, Marlene Gebauer, Carlos Ponce, and Ricardo A. Cabeza. 2018. "LeNRT1.1 Improves Nitrate Uptake in Grafted Tomato Plants under High Nitrogen Demand" International Journal of Molecular Sciences 19, no. 12: 3921. https://doi.org/10.3390/ijms19123921
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